CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of copending U.S. Provisional Application Ser. No. 60/058,569, filed Sep. 11, 1997.
1. Field of the Invention
This invention relates to alarm systems for high water conditions in water, waste-water or sewage treatment systems and tanks and more particularly, to a pressure-reducing apparatus attached to the air supply line of a treatment system or tank for effecting a reduction in the incoming aeration air pressure and a pressure-sensing system attached to the air supply compressor or mounted in or on the air supply line for indicating the pressure reduction by audible and/or visual alarms. In a preferred embodiment the pressure-reducing element includes a fitting such as a tee or elbow located in the incoming aeration air pressure line, a nipple which may be perforated in one embodiment and is typically threadably inserted in the leg of the tee or elbow, a slotted collar may be provided in the nipple in the perforated nipple embodiment of the invention and a float is extended below the nipple and is provided with a rod, shaft or neck that extends through the nipple and the tee leg or elbow and terminates at an air deflector that normally seats in the mouth of the nipple. According to the method of this invention, under conditions of high water or sewage in the treatment tank or system, the float is displaced upwardly, thus projecting the air deflector into the run of the tee or into the elbow, and causing a pressure drop through the tee or elbow, as air is deflected through the float neck or the collar slots and the perforations in the nipple mounted in the tee leg or elbow. This reduction in pressure is sensed by a pressure-sensing switch and control circuit mounted on a conventional air compressor or blower or in the air supply line, which control circuit typically includes audible and visual alarms for alerting treatment tank or system personnel as to the abnormally high water or sewage condition.
2. Description of the Prior Art
A variety of techniques and systems have been developed for detecting high water in waste-water and sewage treatment tanks and systems. Many of these devices are electrical in nature and depend upon a float mechanism of various design, which causes a short or other disrupted electrical connection under conditions of high water in the tank or system monitored, to thus sound an alarm and alert treatment tank or system personnel. Typical of these devices is the "Liquid Level Controlling Device" detailed in U.S. Pat. No. 3,104,678, dated Sep. 24, 1963, to Cole. The fluid controlling apparatus includes a pneumatic, single-diaphragm control mechanism coupled to a liquid supply control valve, for controlling the level of a liquid in a tank or vessel. U.S. Pat. No. 3,358,507, dated Dec. 19, 1967, to Montgomery, details a "Septic Tank Sludge Indicator" which includes an outer tube and an inner tube provided in the outer tube, with multiple selenium cells connected in parallel to each other and located within the inner tube. A light source is located adjacent to the outer tube, such that electric current emitted from the selenium cells and lighting the light is a function of the thickness of the sludge in the tank. U.S. Pat. No. 3,583,437, dated Jun. 8, 1971, to Mastroianni, details a "Whiteprint Duplicating Machine Liquid Supply System", which includes a metering device and a reservoir which receives a liquid developer. A pump elevates liquid from the bottom of a container to the top of the reservoir and a relay energizes a signal device such as a lamp or buzzer if the liquid level in the reservoir falls below a vertical air pipe connected to an air-sensitive switch and the reservoir. U.S. Pat. No. 3,858,602, dated Jan. 7, 1975, to Brym, details an "Air Operated Safety Shutoff System For Liquid Reservoir Feed". The system is designed to control the level liquid in a container and includes a pressurized air system for maintaining a valve in a liquid feed system in the open condition. A valve in a safety alarm system is closed during normal safe operation and any unsafe condition depressurizes the system to close the liquid feed line and engage the safety valve. A "Septic Tank System" is detailed in U.S. Pat. No. 3,954,612, dated May 4, 1976, to Wilkerson. The system is provided with an indicator above the ground surface to indicate the water level and the tributaries leading from the tank, so that any excess water in the tank may be pumped out of the tank before it causes backup of sewage upstream in the septic tank. U.S. Pat. No. 4,129,038, dated Dec. 12, 1978, to Leutenegger, details an "Apparatus For Indicating the Level of Liquids in the Containers or Watercraft". The compartment or container includes a float connected to a piston by a vertical piston rod. The piston rises in a cylinder when the float rises in response to admission of liquid into the compartment, such that the piston effects two timely spaced compressions of a confined gas, which actuates a pilot valve for a flow-regulating valve when the pressure of the confined gas reaches a preselected value. Warning signals are provided for signaling "full" and "empty" conditions of the tank or compartment. An "Automatic Tank Reading Gauge" is detailed in U.S. Pat. No. 4,890,493, dated Jan. 2, 1990, to Johnson et al. The device includes an elongated, flexible measuring member having a scale with a float affixed to one end and a counterweight at the other end. A measuring member is positioned within an O-shaped body having a weep hole, an air check valve and a top sight area. When the body is placed through a filler hole to extend to the bottom of a tank, the volume of fluid within the tank is indicated at the top sight area. U.S. Pat. No. 5,549,818, dated Aug. 27, 1996, to McGrew, details a "Sewage Treatment System", including a cylindrical tank fitted with an air distribution system for aerating the sewage in the tank. The tank is typical of the system in which the pressure alarm for sewage treatment of this invention can be utilized.
It is an object of this invention to provide a pressure alarm and method of operation for water and sewage treatment systems, including treatment tanks and vessels, which alarm is characterized by a float-type pressure-reducing element that responds to a high water or sewage condition in the tank or vessel and reduces air pressure in the air supply system and a pressure-sensing element that senses this reduction in the pressure of the aeration air flowing into the tank, to sound and/or visually indicate an alarm.
Another object of the invention is to provide a pressure alarm and method of operation for sewage and waste-water treatment systems, which alarm includes a pressure-reducing apparatus, typically including a tee or elbow located in the aeration air line entering the system or tank, a float located beneath the tee or elbow and aligned with a pipe or nipple, which may be perforated and is typically threaded into the tee or elbow leg and a shaft or neck connecting the float to an air deflector normally seated in the top of the nipple inside the line. According to the method of this invention the air deflector is designed to extend upwardly into the tee run or elbow when the water or sewage rises abnormally high in the tank or vessel, responsive to flotation of the float and air pressure is reduced in the tee run or elbow and the air line, as air is diverted from the tee run or elbow through the float neck or the perforations in the pipe or nipple.
Still another object of this invention is to provide a pressure alarm for sewage and waste-water treatment tanks and a method for indicating a high water or sewage condition in a tank or vessel, which alarm includes a pressure-reducing air deflector system for deflecting air from the aeration air line extending into the tank responsive to operation of a float, wherein the pressure reduction in the aeration air line is sensed by a pressure-sensing switch and control system mounted on a pump or blower or in or on the aeration air line, for indicating, visually, audibly or both, the high water or sewage condition in the tank.
Yet another object of this invention is to provide a new and improved pressure alarm and method for sewage treatment tanks and systems, which alarm system includes a pressure-reducing apparatus characterized by a tee or an elbow located in the aeration line extending into the tank, a nipple, (which may be perforated), threaded into or otherwise seated in the tee leg of the tee or in the elbow, a ball float located beneath the tee or elbow and the nipple and fitted with a shaft or ball neck projecting through the nipple and terminating in an air deflector which normally seats in the mouth of the nipple and allows air to flow freely through the run of the tee, or to bypass the elbow. The air is caused to flow through the aeration line and tee run and normally bypass the elbow by means of a conventional pump or blower which is typically fitted with a pressure-sensing switch and control system for monitoring the pressure of the aeration air. According to the method of this invention, when a high water or sewage condition exists in the tank, the buoyant ball float is forced upwardly, thereby elevating the air deflector into the run of the tee or into the elbow and deflecting air through the nipple and the air spaces or passages in the ball neck or the perforations in the nipple, thus reducing the pressure of the air in the run of the tee or elbow. This pressure reduction is sensed by the pressure switch mounted on the blower or pump or elsewhere pneumatically connected to the aeration line. This decrease in air pressure triggers either a visual, audible or both, alarm by operation of the pressure switch control system, thus indicating the high water condition in the tank or system.
Another object of this invention is to provide a method for indicating a high water, waste-water or sewage condition in a tank or vessel by pressure differential, which method includes the steps of providing a float beneath an air supply line to the tank or vessel; mounting an air deflector on the float for extension into the air supply line responsive to flotation of the float with the high water or sewage and diverting air from the air supply line to create a pressure reduction in the air supply line; providing a pressure-sensing device in pneumatic association with the air supply line for sensing the pressure reduction in the air supply line; and providing an alarm system in association with the pressure-sensing device for indicating an alarm in the high water or sewage condition.